The -n rule: sommige or sommigen, beide or beiden

Words like sommige (some) and beide (both) sometimes get an extra -n: Sommigen kwamen te laat (Some people arrived late) but sommige mensen (some people). One test decides it.

Add -n only when the word stands on its own and refers to people; in every other case leave it off. Check two things:

1. Is there a noun right after the word (or could you add one)? Then no -n: sommige studenten (some students), beide boeken (both books). The word describes the noun, so it stays sommige, beide.
2. Does the word stand alone, and does it point to people? Then add -n: Sommigen zeiden niets (Some [people] said nothing), Beiden hebben gelijk (Both [of them] are right).

If the standalone word points to things or animals rather than people, it keeps its plain form: Ik heb twee fietsen; beide zijn kapot. (I have two bikes; both are broken.)

The same rule runs across a small family of quantity words. Each has a plain form (before a noun or for things) and an -n form (standing alone for people).

• Before a noun: Enkele gasten bleven staan. (A few guests remained standing.)
• Standing alone, people: Enkelen bleven staan. (A few [people] remained standing.)
• Standing alone, people: Velen geloven dat niet. (Many [people] do not believe that.)
• Standing alone, people: Allen waren welkom. (Everyone was welcome.)

These words belong to the wider set of quantity words covered in all and every and some, several, few, many; this page is only about the -n.

The usual slip is adding -n before a noun: sommigen mensen is wrong, because a noun (mensen) follows — it must be sommige mensen. The -n form replaces the noun; it never sits in front of one. So Sommigen kwamen (no noun, people) is right, but as soon as you name the noun, drop the -n: Sommige bezoekers kwamen.